Ephesians 4:24 (NKJV)
... put on the new man which was created according to God, in true righteousness and holiness.
Every morning you have a choice to make when you get dressed, this shirt or that shirt. If you are born again, you have two natures within you. You have to make a conscious choice at every juncture in your life. What will I put on, the old nature or the new nature.
The most wonderful thing is that your new nature is truly righteous and holy! Sounds like an easy choice to me.